GB956367A - Improvements in or relating to photographic cameras with coupled photoelectric exposure meters - Google Patents

Abstract

956,367. Photographic cameras. ZEISS IKON A.G. Aug. 3, 1960 [Aug. 4, 1959], No. 26944/60. Heading G2A. A photographic camera having a photo-electric exposure meter coupled to exposure value setting means of the camera has a reading position visible in the view-finder of the camera and/or through a window in the camera housing, and, in addition to a follower pointer in the case of a fixed meter or a fixed countermark in the case of a movably mounted meter,there is provided at least one movably mounted compensating marker the position of which, in use, is always so related to that of the said follower pointer or fixed countermark as to cause a predetermined compensation factor to be applied to the exposure value setting when such marker and the exposure meter pointer are brought into coincidence. In a first embodiment, as shown, an angularly shaped pointer 3 of a rotatably mounted galvonometer 1 is visible through a window 5 in a camera wall 2 and also through an adjustably poistioned window 6a of a viewfinder 29 shown as a pentaprism type finder for a singlelens reflex camera. On adjustment of the exposure value setting means (not shown) on the camera, a gear wheel 8 is rotated and, by way of a cam disc 11 rotatable therewith, a cam follower 14 mounted on a pivoted toothed segment 18 and by pinions 20- 22,the galvanometer casing 1 is thereby also rotated for bringing the pointer 3 into registry with a fixed counter mark 4 or a corresponding mark in the outline of the window 6a. Alternatively if it is desired to make allowance for a different film sensitivity or a filter factor,the pointer 3 may be brought into coincidence with either of two compensating markers 12 or 12a which are respectively carried on arms 16b, 16a of a lever 16 having a pivot 17 and a follower pin 13 for engaging under spring loading with a further cam disc 10 rotatable with the gear-wheel 8. The markers 12 and 12a are spaced from the counter marks 4 and 6a respectively by an amount corresponding to one light value or one aperture stop and the cam 10 is designed to correct for the non- linearity of the pointer position which has not been wholly corrected by the cam 11. The mirror 7 is provided for illumination purposes, directing light through the mask 6 and into the view finder. In modifications (Figs. 8 and 9 not shown), more than one marker bearing lever 16 may be provided, each spaced from the next by an amount corresponding to one light value or one aperture stop, and each being controlled either by separate cam discs 10 or by separate cam followers 13 engaging at different points with the same cam disc 10. In an alternative embodiment (Fig.3 not shown), the galvanometer is non-rotatably mounted, a followup pointer adjustable by the cam 11 is provided, and markers 12 and 12a are similarly provided on a lever 16 which is so controlled by a cam disc that it follows the movements of the follow-up pointer at a spacing corresponding to one light value or one aperture stop.